1 #ifndef IO_URING_TYPES_H
2 #define IO_URING_TYPES_H
3
4 #include <linux/blkdev.h>
5 #include <linux/hashtable.h>
6 #include <linux/task_work.h>
7 #include <linux/bitmap.h>
8 #include <linux/llist.h>
9 #include <uapi/linux/io_uring.h>
10
11 enum {
12 /*
13 * A hint to not wake right away but delay until there are enough of
14 * tw's queued to match the number of CQEs the task is waiting for.
15 *
16 * Must not be used with requests generating more than one CQE.
17 * It's also ignored unless IORING_SETUP_DEFER_TASKRUN is set.
18 */
19 IOU_F_TWQ_LAZY_WAKE = 1,
20 };
21
22 enum io_uring_cmd_flags {
23 IO_URING_F_COMPLETE_DEFER = 1,
24 IO_URING_F_UNLOCKED = 2,
25 /* the request is executed from poll, it should not be freed */
26 IO_URING_F_MULTISHOT = 4,
27 /* executed by io-wq */
28 IO_URING_F_IOWQ = 8,
29 /* executed inline from syscall */
30 IO_URING_F_INLINE = 16,
31 /* int's last bit, sign checks are usually faster than a bit test */
32 IO_URING_F_NONBLOCK = INT_MIN,
33
34 /* ctx state flags, for URING_CMD */
35 IO_URING_F_SQE128 = (1 << 8),
36 IO_URING_F_CQE32 = (1 << 9),
37 IO_URING_F_IOPOLL = (1 << 10),
38
39 /* set when uring wants to cancel a previously issued command */
40 IO_URING_F_CANCEL = (1 << 11),
41 IO_URING_F_COMPAT = (1 << 12),
42 IO_URING_F_TASK_DEAD = (1 << 13),
43 };
44
45 struct io_wq_work_node {
46 struct io_wq_work_node *next;
47 };
48
49 struct io_wq_work_list {
50 struct io_wq_work_node *first;
51 struct io_wq_work_node *last;
52 };
53
54 struct io_wq_work {
55 struct io_wq_work_node list;
56 atomic_t flags;
57 /* place it here instead of io_kiocb as it fills padding and saves 4B */
58 int cancel_seq;
59 };
60
61 struct io_rsrc_data {
62 unsigned int nr;
63 struct io_rsrc_node **nodes;
64 };
65
66 struct io_file_table {
67 struct io_rsrc_data data;
68 unsigned long *bitmap;
69 unsigned int alloc_hint;
70 };
71
72 struct io_hash_bucket {
73 struct hlist_head list;
74 } ____cacheline_aligned_in_smp;
75
76 struct io_hash_table {
77 struct io_hash_bucket *hbs;
78 unsigned hash_bits;
79 };
80
81 struct io_mapped_region {
82 struct page **pages;
83 void *ptr;
84 unsigned nr_pages;
85 unsigned flags;
86 };
87
88 /*
89 * Return value from io_buffer_list selection, to avoid stashing it in
90 * struct io_kiocb. For legacy/classic provided buffers, keeping a reference
91 * across execution contexts are fine. But for ring provided buffers, the
92 * list may go away as soon as ->uring_lock is dropped. As the io_kiocb
93 * persists, it's better to just keep the buffer local for those cases.
94 */
95 struct io_br_sel {
96 struct io_buffer_list *buf_list;
97 /*
98 * Some selection parts return the user address, others return an error.
99 */
100 union {
101 void __user *addr;
102 ssize_t val;
103 };
104 };
105
106
107 /*
108 * Arbitrary limit, can be raised if need be
109 */
110 #define IO_RINGFD_REG_MAX 16
111
112 struct io_uring_task {
113 /* submission side */
114 int cached_refs;
115 const struct io_ring_ctx *last;
116 struct task_struct *task;
117 struct io_wq *io_wq;
118 struct file *registered_rings[IO_RINGFD_REG_MAX];
119
120 struct xarray xa;
121 struct wait_queue_head wait;
122 atomic_t in_cancel;
123 atomic_t inflight_tracked;
124 struct percpu_counter inflight;
125
126 struct { /* task_work */
127 struct llist_head task_list;
128 struct callback_head task_work;
129 } ____cacheline_aligned_in_smp;
130 };
131
132 struct iou_vec {
133 union {
134 struct iovec *iovec;
135 struct bio_vec *bvec;
136 };
137 unsigned nr; /* number of struct iovec it can hold */
138 };
139
140 struct io_uring {
141 u32 head;
142 u32 tail;
143 };
144
145 /*
146 * This data is shared with the application through the mmap at offsets
147 * IORING_OFF_SQ_RING and IORING_OFF_CQ_RING.
148 *
149 * The offsets to the member fields are published through struct
150 * io_sqring_offsets when calling io_uring_setup.
151 */
152 struct io_rings {
153 /*
154 * Head and tail offsets into the ring; the offsets need to be
155 * masked to get valid indices.
156 *
157 * The kernel controls head of the sq ring and the tail of the cq ring,
158 * and the application controls tail of the sq ring and the head of the
159 * cq ring.
160 */
161 struct io_uring sq, cq;
162 /*
163 * Bitmasks to apply to head and tail offsets (constant, equals
164 * ring_entries - 1)
165 */
166 u32 sq_ring_mask, cq_ring_mask;
167 /* Ring sizes (constant, power of 2) */
168 u32 sq_ring_entries, cq_ring_entries;
169 /*
170 * Number of invalid entries dropped by the kernel due to
171 * invalid index stored in array
172 *
173 * Written by the kernel, shouldn't be modified by the
174 * application (i.e. get number of "new events" by comparing to
175 * cached value).
176 *
177 * After a new SQ head value was read by the application this
178 * counter includes all submissions that were dropped reaching
179 * the new SQ head (and possibly more).
180 */
181 u32 sq_dropped;
182 /*
183 * Runtime SQ flags
184 *
185 * Written by the kernel, shouldn't be modified by the
186 * application.
187 *
188 * The application needs a full memory barrier before checking
189 * for IORING_SQ_NEED_WAKEUP after updating the sq tail.
190 */
191 atomic_t sq_flags;
192 /*
193 * Runtime CQ flags
194 *
195 * Written by the application, shouldn't be modified by the
196 * kernel.
197 */
198 u32 cq_flags;
199 /*
200 * Number of completion events lost because the queue was full;
201 * this should be avoided by the application by making sure
202 * there are not more requests pending than there is space in
203 * the completion queue.
204 *
205 * Written by the kernel, shouldn't be modified by the
206 * application (i.e. get number of "new events" by comparing to
207 * cached value).
208 *
209 * As completion events come in out of order this counter is not
210 * ordered with any other data.
211 */
212 u32 cq_overflow;
213 /*
214 * Ring buffer of completion events.
215 *
216 * The kernel writes completion events fresh every time they are
217 * produced, so the application is allowed to modify pending
218 * entries.
219 */
220 struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp;
221 };
222
223 struct io_restriction {
224 DECLARE_BITMAP(register_op, IORING_REGISTER_LAST);
225 DECLARE_BITMAP(sqe_op, IORING_OP_LAST);
226 u8 sqe_flags_allowed;
227 u8 sqe_flags_required;
228 bool registered;
229 };
230
231 struct io_submit_link {
232 struct io_kiocb *head;
233 struct io_kiocb *last;
234 };
235
236 struct io_submit_state {
237 /* inline/task_work completion list, under ->uring_lock */
238 struct io_wq_work_node free_list;
239 /* batch completion logic */
240 struct io_wq_work_list compl_reqs;
241 struct io_submit_link link;
242
243 bool plug_started;
244 bool need_plug;
245 bool cq_flush;
246 unsigned short submit_nr;
247 struct blk_plug plug;
248 };
249
250 struct io_alloc_cache {
251 void **entries;
252 unsigned int nr_cached;
253 unsigned int max_cached;
254 unsigned int elem_size;
255 unsigned int init_clear;
256 };
257
258 struct io_ring_ctx {
259 /* const or read-mostly hot data */
260 struct {
261 unsigned int flags;
262 unsigned int drain_next: 1;
263 unsigned int restricted: 1;
264 unsigned int off_timeout_used: 1;
265 unsigned int drain_active: 1;
266 unsigned int has_evfd: 1;
267 /* all CQEs should be posted only by the submitter task */
268 unsigned int task_complete: 1;
269 unsigned int lockless_cq: 1;
270 unsigned int syscall_iopoll: 1;
271 unsigned int poll_activated: 1;
272 unsigned int drain_disabled: 1;
273 unsigned int compat: 1;
274 unsigned int iowq_limits_set : 1;
275
276 struct task_struct *submitter_task;
277 struct io_rings *rings;
278 struct percpu_ref refs;
279
280 clockid_t clockid;
281 enum tk_offsets clock_offset;
282
283 enum task_work_notify_mode notify_method;
284 unsigned sq_thread_idle;
285 } ____cacheline_aligned_in_smp;
286
287 /* submission data */
288 struct {
289 struct mutex uring_lock;
290
291 /*
292 * Ring buffer of indices into array of io_uring_sqe, which is
293 * mmapped by the application using the IORING_OFF_SQES offset.
294 *
295 * This indirection could e.g. be used to assign fixed
296 * io_uring_sqe entries to operations and only submit them to
297 * the queue when needed.
298 *
299 * The kernel modifies neither the indices array nor the entries
300 * array.
301 */
302 u32 *sq_array;
303 struct io_uring_sqe *sq_sqes;
304 unsigned cached_sq_head;
305 unsigned sq_entries;
306
307 /*
308 * Fixed resources fast path, should be accessed only under
309 * uring_lock, and updated through io_uring_register(2)
310 */
311 atomic_t cancel_seq;
312
313 /*
314 * ->iopoll_list is protected by the ctx->uring_lock for
315 * io_uring instances that don't use IORING_SETUP_SQPOLL.
316 * For SQPOLL, only the single threaded io_sq_thread() will
317 * manipulate the list, hence no extra locking is needed there.
318 */
319 bool poll_multi_queue;
320 struct io_wq_work_list iopoll_list;
321
322 struct io_file_table file_table;
323 struct io_rsrc_data buf_table;
324 struct io_alloc_cache node_cache;
325 struct io_alloc_cache imu_cache;
326
327 struct io_submit_state submit_state;
328
329 /*
330 * Modifications are protected by ->uring_lock and ->mmap_lock.
331 * The flags, buf_pages and buf_nr_pages fields should be stable
332 * once published.
333 */
334 struct xarray io_bl_xa;
335
336 struct io_hash_table cancel_table;
337 struct io_alloc_cache apoll_cache;
338 struct io_alloc_cache netmsg_cache;
339 struct io_alloc_cache rw_cache;
340 struct io_alloc_cache cmd_cache;
341
342 /*
343 * Any cancelable uring_cmd is added to this list in
344 * ->uring_cmd() by io_uring_cmd_insert_cancelable()
345 */
346 struct hlist_head cancelable_uring_cmd;
347 /*
348 * For Hybrid IOPOLL, runtime in hybrid polling, without
349 * scheduling time
350 */
351 u64 hybrid_poll_time;
352 } ____cacheline_aligned_in_smp;
353
354 struct {
355 /*
356 * We cache a range of free CQEs we can use, once exhausted it
357 * should go through a slower range setup, see __io_get_cqe()
358 */
359 struct io_uring_cqe *cqe_cached;
360 struct io_uring_cqe *cqe_sentinel;
361
362 unsigned cached_cq_tail;
363 unsigned cq_entries;
364 struct io_ev_fd __rcu *io_ev_fd;
365
366 void *cq_wait_arg;
367 size_t cq_wait_size;
368 } ____cacheline_aligned_in_smp;
369
370 /*
371 * task_work and async notification delivery cacheline. Expected to
372 * regularly bounce b/w CPUs.
373 */
374 struct {
375 struct llist_head work_llist;
376 struct llist_head retry_llist;
377 unsigned long check_cq;
378 atomic_t cq_wait_nr;
379 atomic_t cq_timeouts;
380 struct wait_queue_head cq_wait;
381 } ____cacheline_aligned_in_smp;
382
383 /* timeouts */
384 struct {
385 raw_spinlock_t timeout_lock;
386 struct list_head timeout_list;
387 struct list_head ltimeout_list;
388 unsigned cq_last_tm_flush;
389 } ____cacheline_aligned_in_smp;
390
391 spinlock_t completion_lock;
392
393 struct list_head cq_overflow_list;
394
395 struct hlist_head waitid_list;
396
397 #ifdef CONFIG_FUTEX
398 struct hlist_head futex_list;
399 struct io_alloc_cache futex_cache;
400 #endif
401
402 const struct cred *sq_creds; /* cred used for __io_sq_thread() */
403 struct io_sq_data *sq_data; /* if using sq thread polling */
404
405 struct wait_queue_head sqo_sq_wait;
406 struct list_head sqd_list;
407
408 unsigned int file_alloc_start;
409 unsigned int file_alloc_end;
410
411 /* Keep this last, we don't need it for the fast path */
412 struct wait_queue_head poll_wq;
413 struct io_restriction restrictions;
414
415 /* Stores zcrx object pointers of type struct io_zcrx_ifq */
416 struct xarray zcrx_ctxs;
417
418 u32 pers_next;
419 struct xarray personalities;
420
421 /* hashed buffered write serialization */
422 struct io_wq_hash *hash_map;
423
424 /* Only used for accounting purposes */
425 struct user_struct *user;
426 struct mm_struct *mm_account;
427
428 /* ctx exit and cancelation */
429 struct llist_head fallback_llist;
430 struct delayed_work fallback_work;
431 struct work_struct exit_work;
432 struct list_head tctx_list;
433 struct completion ref_comp;
434
435 /* io-wq management, e.g. thread count */
436 u32 iowq_limits[2];
437
438 struct callback_head poll_wq_task_work;
439 struct list_head defer_list;
440 unsigned nr_drained;
441
442 #ifdef CONFIG_NET_RX_BUSY_POLL
443 struct list_head napi_list; /* track busy poll napi_id */
444 spinlock_t napi_lock; /* napi_list lock */
445
446 /* napi busy poll default timeout */
447 ktime_t napi_busy_poll_dt;
448 bool napi_prefer_busy_poll;
449 u8 napi_track_mode;
450
451 DECLARE_HASHTABLE(napi_ht, 4);
452 #endif
453
454 /* protected by ->completion_lock */
455 unsigned evfd_last_cq_tail;
456 unsigned nr_req_allocated;
457
458 /*
459 * Protection for resize vs mmap races - both the mmap and resize
460 * side will need to grab this lock, to prevent either side from
461 * being run concurrently with the other.
462 */
463 struct mutex mmap_lock;
464
465 struct io_mapped_region sq_region;
466 struct io_mapped_region ring_region;
467 /* used for optimised request parameter and wait argument passing */
468 struct io_mapped_region param_region;
469 };
470
471 /*
472 * Token indicating function is called in task work context:
473 * ctx->uring_lock is held and any completions generated will be flushed.
474 * ONLY core io_uring.c should instantiate this struct.
475 */
476 struct io_tw_state {
477 };
478 /* Alias to use in code that doesn't instantiate struct io_tw_state */
479 typedef struct io_tw_state io_tw_token_t;
480
481 enum {
482 REQ_F_FIXED_FILE_BIT = IOSQE_FIXED_FILE_BIT,
483 REQ_F_IO_DRAIN_BIT = IOSQE_IO_DRAIN_BIT,
484 REQ_F_LINK_BIT = IOSQE_IO_LINK_BIT,
485 REQ_F_HARDLINK_BIT = IOSQE_IO_HARDLINK_BIT,
486 REQ_F_FORCE_ASYNC_BIT = IOSQE_ASYNC_BIT,
487 REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT,
488 REQ_F_CQE_SKIP_BIT = IOSQE_CQE_SKIP_SUCCESS_BIT,
489
490 /* first byte is taken by user flags, shift it to not overlap */
491 REQ_F_FAIL_BIT = 8,
492 REQ_F_INFLIGHT_BIT,
493 REQ_F_CUR_POS_BIT,
494 REQ_F_NOWAIT_BIT,
495 REQ_F_LINK_TIMEOUT_BIT,
496 REQ_F_NEED_CLEANUP_BIT,
497 REQ_F_POLLED_BIT,
498 REQ_F_HYBRID_IOPOLL_STATE_BIT,
499 REQ_F_BUFFER_SELECTED_BIT,
500 REQ_F_BUFFER_RING_BIT,
501 REQ_F_REISSUE_BIT,
502 REQ_F_CREDS_BIT,
503 REQ_F_REFCOUNT_BIT,
504 REQ_F_ARM_LTIMEOUT_BIT,
505 REQ_F_ASYNC_DATA_BIT,
506 REQ_F_SKIP_LINK_CQES_BIT,
507 REQ_F_SINGLE_POLL_BIT,
508 REQ_F_DOUBLE_POLL_BIT,
509 REQ_F_MULTISHOT_BIT,
510 REQ_F_APOLL_MULTISHOT_BIT,
511 REQ_F_CLEAR_POLLIN_BIT,
512 /* keep async read/write and isreg together and in order */
513 REQ_F_SUPPORT_NOWAIT_BIT,
514 REQ_F_ISREG_BIT,
515 REQ_F_POLL_NO_LAZY_BIT,
516 REQ_F_CAN_POLL_BIT,
517 REQ_F_BL_EMPTY_BIT,
518 REQ_F_BL_NO_RECYCLE_BIT,
519 REQ_F_BUFFERS_COMMIT_BIT,
520 REQ_F_BUF_NODE_BIT,
521 REQ_F_HAS_METADATA_BIT,
522 REQ_F_IMPORT_BUFFER_BIT,
523 REQ_F_SQE_COPIED_BIT,
524
525 /* not a real bit, just to check we're not overflowing the space */
526 __REQ_F_LAST_BIT,
527 };
528
529 typedef u64 __bitwise io_req_flags_t;
530 #define IO_REQ_FLAG(bitno) ((__force io_req_flags_t) BIT_ULL((bitno)))
531
532 enum {
533 /* ctx owns file */
534 REQ_F_FIXED_FILE = IO_REQ_FLAG(REQ_F_FIXED_FILE_BIT),
535 /* drain existing IO first */
536 REQ_F_IO_DRAIN = IO_REQ_FLAG(REQ_F_IO_DRAIN_BIT),
537 /* linked sqes */
538 REQ_F_LINK = IO_REQ_FLAG(REQ_F_LINK_BIT),
539 /* doesn't sever on completion < 0 */
540 REQ_F_HARDLINK = IO_REQ_FLAG(REQ_F_HARDLINK_BIT),
541 /* IOSQE_ASYNC */
542 REQ_F_FORCE_ASYNC = IO_REQ_FLAG(REQ_F_FORCE_ASYNC_BIT),
543 /* IOSQE_BUFFER_SELECT */
544 REQ_F_BUFFER_SELECT = IO_REQ_FLAG(REQ_F_BUFFER_SELECT_BIT),
545 /* IOSQE_CQE_SKIP_SUCCESS */
546 REQ_F_CQE_SKIP = IO_REQ_FLAG(REQ_F_CQE_SKIP_BIT),
547
548 /* fail rest of links */
549 REQ_F_FAIL = IO_REQ_FLAG(REQ_F_FAIL_BIT),
550 /* on inflight list, should be cancelled and waited on exit reliably */
551 REQ_F_INFLIGHT = IO_REQ_FLAG(REQ_F_INFLIGHT_BIT),
552 /* read/write uses file position */
553 REQ_F_CUR_POS = IO_REQ_FLAG(REQ_F_CUR_POS_BIT),
554 /* must not punt to workers */
555 REQ_F_NOWAIT = IO_REQ_FLAG(REQ_F_NOWAIT_BIT),
556 /* has or had linked timeout */
557 REQ_F_LINK_TIMEOUT = IO_REQ_FLAG(REQ_F_LINK_TIMEOUT_BIT),
558 /* needs cleanup */
559 REQ_F_NEED_CLEANUP = IO_REQ_FLAG(REQ_F_NEED_CLEANUP_BIT),
560 /* already went through poll handler */
561 REQ_F_POLLED = IO_REQ_FLAG(REQ_F_POLLED_BIT),
562 /* every req only blocks once in hybrid poll */
563 REQ_F_IOPOLL_STATE = IO_REQ_FLAG(REQ_F_HYBRID_IOPOLL_STATE_BIT),
564 /* buffer already selected */
565 REQ_F_BUFFER_SELECTED = IO_REQ_FLAG(REQ_F_BUFFER_SELECTED_BIT),
566 /* buffer selected from ring, needs commit */
567 REQ_F_BUFFER_RING = IO_REQ_FLAG(REQ_F_BUFFER_RING_BIT),
568 /* caller should reissue async */
569 REQ_F_REISSUE = IO_REQ_FLAG(REQ_F_REISSUE_BIT),
570 /* supports async reads/writes */
571 REQ_F_SUPPORT_NOWAIT = IO_REQ_FLAG(REQ_F_SUPPORT_NOWAIT_BIT),
572 /* regular file */
573 REQ_F_ISREG = IO_REQ_FLAG(REQ_F_ISREG_BIT),
574 /* has creds assigned */
575 REQ_F_CREDS = IO_REQ_FLAG(REQ_F_CREDS_BIT),
576 /* skip refcounting if not set */
577 REQ_F_REFCOUNT = IO_REQ_FLAG(REQ_F_REFCOUNT_BIT),
578 /* there is a linked timeout that has to be armed */
579 REQ_F_ARM_LTIMEOUT = IO_REQ_FLAG(REQ_F_ARM_LTIMEOUT_BIT),
580 /* ->async_data allocated */
581 REQ_F_ASYNC_DATA = IO_REQ_FLAG(REQ_F_ASYNC_DATA_BIT),
582 /* don't post CQEs while failing linked requests */
583 REQ_F_SKIP_LINK_CQES = IO_REQ_FLAG(REQ_F_SKIP_LINK_CQES_BIT),
584 /* single poll may be active */
585 REQ_F_SINGLE_POLL = IO_REQ_FLAG(REQ_F_SINGLE_POLL_BIT),
586 /* double poll may active */
587 REQ_F_DOUBLE_POLL = IO_REQ_FLAG(REQ_F_DOUBLE_POLL_BIT),
588 /* request posts multiple completions, should be set at prep time */
589 REQ_F_MULTISHOT = IO_REQ_FLAG(REQ_F_MULTISHOT_BIT),
590 /* fast poll multishot mode */
591 REQ_F_APOLL_MULTISHOT = IO_REQ_FLAG(REQ_F_APOLL_MULTISHOT_BIT),
592 /* recvmsg special flag, clear EPOLLIN */
593 REQ_F_CLEAR_POLLIN = IO_REQ_FLAG(REQ_F_CLEAR_POLLIN_BIT),
594 /* don't use lazy poll wake for this request */
595 REQ_F_POLL_NO_LAZY = IO_REQ_FLAG(REQ_F_POLL_NO_LAZY_BIT),
596 /* file is pollable */
597 REQ_F_CAN_POLL = IO_REQ_FLAG(REQ_F_CAN_POLL_BIT),
598 /* buffer list was empty after selection of buffer */
599 REQ_F_BL_EMPTY = IO_REQ_FLAG(REQ_F_BL_EMPTY_BIT),
600 /* don't recycle provided buffers for this request */
601 REQ_F_BL_NO_RECYCLE = IO_REQ_FLAG(REQ_F_BL_NO_RECYCLE_BIT),
602 /* buffer ring head needs incrementing on put */
603 REQ_F_BUFFERS_COMMIT = IO_REQ_FLAG(REQ_F_BUFFERS_COMMIT_BIT),
604 /* buf node is valid */
605 REQ_F_BUF_NODE = IO_REQ_FLAG(REQ_F_BUF_NODE_BIT),
606 /* request has read/write metadata assigned */
607 REQ_F_HAS_METADATA = IO_REQ_FLAG(REQ_F_HAS_METADATA_BIT),
608 /*
609 * For vectored fixed buffers, resolve iovec to registered buffers.
610 * For SEND_ZC, whether to import buffers (i.e. the first issue).
611 */
612 REQ_F_IMPORT_BUFFER = IO_REQ_FLAG(REQ_F_IMPORT_BUFFER_BIT),
613 /* ->sqe_copy() has been called, if necessary */
614 REQ_F_SQE_COPIED = IO_REQ_FLAG(REQ_F_SQE_COPIED_BIT),
615 };
616
617 typedef void (*io_req_tw_func_t)(struct io_kiocb *req, io_tw_token_t tw);
618
619 struct io_task_work {
620 struct llist_node node;
621 io_req_tw_func_t func;
622 };
623
624 struct io_cqe {
625 __u64 user_data;
626 __s32 res;
627 /* fd initially, then cflags for completion */
628 union {
629 __u32 flags;
630 int fd;
631 };
632 };
633
634 /*
635 * Each request type overlays its private data structure on top of this one.
636 * They must not exceed this one in size.
637 */
638 struct io_cmd_data {
639 struct file *file;
640 /* each command gets 56 bytes of data */
641 __u8 data[56];
642 };
643
io_kiocb_cmd_sz_check(size_t cmd_sz)644 static inline void io_kiocb_cmd_sz_check(size_t cmd_sz)
645 {
646 BUILD_BUG_ON(cmd_sz > sizeof(struct io_cmd_data));
647 }
648 #define io_kiocb_to_cmd(req, cmd_type) ( \
649 io_kiocb_cmd_sz_check(sizeof(cmd_type)) , \
650 ((cmd_type *)&(req)->cmd) \
651 )
652
cmd_to_io_kiocb(void * ptr)653 static inline struct io_kiocb *cmd_to_io_kiocb(void *ptr)
654 {
655 return ptr;
656 }
657
658 struct io_kiocb {
659 union {
660 /*
661 * NOTE! Each of the io_kiocb union members has the file pointer
662 * as the first entry in their struct definition. So you can
663 * access the file pointer through any of the sub-structs,
664 * or directly as just 'file' in this struct.
665 */
666 struct file *file;
667 struct io_cmd_data cmd;
668 };
669
670 u8 opcode;
671 /* polled IO has completed */
672 u8 iopoll_completed;
673 /*
674 * Can be either a fixed buffer index, or used with provided buffers.
675 * For the latter, it points to the selected buffer ID.
676 */
677 u16 buf_index;
678
679 unsigned nr_tw;
680
681 /* REQ_F_* flags */
682 io_req_flags_t flags;
683
684 struct io_cqe cqe;
685
686 struct io_ring_ctx *ctx;
687 struct io_uring_task *tctx;
688
689 union {
690 /* stores selected buf, valid IFF REQ_F_BUFFER_SELECTED is set */
691 struct io_buffer *kbuf;
692
693 struct io_rsrc_node *buf_node;
694 };
695
696 union {
697 /* used by request caches, completion batching and iopoll */
698 struct io_wq_work_node comp_list;
699 /* cache ->apoll->events */
700 __poll_t apoll_events;
701 };
702
703 struct io_rsrc_node *file_node;
704
705 atomic_t refs;
706 bool cancel_seq_set;
707 struct io_task_work io_task_work;
708 union {
709 /*
710 * for polled requests, i.e. IORING_OP_POLL_ADD and async armed
711 * poll
712 */
713 struct hlist_node hash_node;
714 /* For IOPOLL setup queues, with hybrid polling */
715 u64 iopoll_start;
716 /* for private io_kiocb freeing */
717 struct rcu_head rcu_head;
718 };
719 /* internal polling, see IORING_FEAT_FAST_POLL */
720 struct async_poll *apoll;
721 /* opcode allocated if it needs to store data for async defer */
722 void *async_data;
723 /* linked requests, IFF REQ_F_HARDLINK or REQ_F_LINK are set */
724 atomic_t poll_refs;
725 struct io_kiocb *link;
726 /* custom credentials, valid IFF REQ_F_CREDS is set */
727 const struct cred *creds;
728 struct io_wq_work work;
729
730 struct io_big_cqe {
731 u64 extra1;
732 u64 extra2;
733 } big_cqe;
734 };
735
736 struct io_overflow_cqe {
737 struct list_head list;
738 struct io_uring_cqe cqe;
739 };
740 #endif
741